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1.
An individual based model of fish school reactions: predicting antipredator behaviour as observed in nature 总被引：5，自引：0，他引：5
An object-orientated, two-dimensional, cellular automata (CA) model is developed to describe and predict the schooling behaviour of fish in general, with Norwegian spring-spawning herring, Clupea harengus L., being used as a case study. The CA model is applied to visualize internal school dynamics based on individual decision rules. Several antipredator strategies, such as split , join and vacuole, performed by schools during predator attack, are visualized in the model. The primary driving force of individual fish is based on simple attraction rules. The model includes stochastic elements which assume that individual herring do not have perfect information about their surroundings. Isolation of individual fish from a school during predator attack is also predicted by the model. The disruption of highly organized fish schools, followed by an attack on solitary herring individuals, may be an important tactic for predators feeding on schooling prey. The conceptual CA model identifies patterns and mechanisms both within and between schools that may be important in all schooling fish. Model simulations are compared with observed predator–prey interactions between killer whales, Orcinus orca L., and herring in northern Norway. 相似文献
2.
Friedrich Ladich 《Fish and Fisheries》2019,20(3):552-563
Fishes communicate acoustically under ecological constraints which may modify or hinder signal transmission and detection and may also be risky. This makes it important to know if and to what degree fishes can modify acoustic signalling when key ecological factors—predation pressure, noise and ambient temperature—vary. This paper reviews short‐time effects of the first two factors; the third has been reviewed recently (Ladich, 2018 ). Numerous studies have investigated the effects of predators on fish behaviour, but only a few report changes in calling activity when hearing predator calls as demonstrated when fish responded to played‐back dolphin sounds. Furthermore, swimming sounds of schooling fish may affect predators. Our knowledge on adaptations to natural changes in ambient noise, for example caused by wind or migration between quiet and noisier habitats, is limited. Hearing abilities decrease when ambient noise levels increase (termed masking), in particular in taxa possessing enhanced hearing abilities. High natural and anthropogenic noise regimes, for example vessel noise, alter calling activity in the field and laboratory. Increases in sound pressure levels (Lombard effect) and altered temporal call patterns were also observed, but no switches to higher sound frequencies. In summary, effects of predator calls and noise on sound communication are described in fishes, yet sparsely in contrast to songbirds or whales. Major gaps in our knowledge on potential negative effects of noise on acoustic communication call for more detailed investigation because fishes are keystone species in many aquatic habitats and constitute a major source of protein for humans. 相似文献
3.
Methods for studying spatial behaviour of freshwater fishes in the natural environment 总被引：6，自引：0，他引：6
Spatial behaviour of fishes in fresh and brackish water ranges in temporal scales between localized diel movements, often associated with foraging and predator evasion, to seasonal or life‐cycle related events involving movements between freshwater habitats or freshwater and marine biotopes. Recent technological advances have resulted in dramatic improvements in the range of techniques available for the study of spatial behaviour of freshwater fishes in the natural environment, and broadly may be divided into two categories: capture dependent and capture independent. The former incorporates those methods that rely on sampling marked fish (mark–recapture) or unmarked fish (density estimates, catch per unit effort) over defined scales of time and space in order to derive information on distribution and movement. Captured fish may also be tagged with transmitters that radiate energy, enabling the fish to be tracked and/or environmental data to be gathered. Biochemical analysis of samples from fish, requiring non‐destructive sampling (genetic analysis and scale microchemistry) or destructive sampling (otolith microchemistry) may also provide information on migration and ontogenetic processes. Capture independent techniques include visual observation and video techniques, hydroacoustics and automated fish counting. Catch per unit effort and mark–recapture techniques are most efficient where long‐term fishery or monitoring studies are in place and data on crude spatial and temporal scales are acceptable. They also have the advantages of low technical requirements and low equipment costs. Where specific management or ecological questions are pertinent, recapture independent techniques may be more appropriate. Telemetric methods can provide high resolution information at the individual level, while hydroacoustics is increasingly providing information at the population level in large lake and river environments. Biochemical methods are becoming increasingly useful in determining the extent of population segregation, where DNA analysis is used, and in the study of migration and ontogenetic changes in behaviour, where otolith microchemistry and stable isotope analysis is used. 相似文献
4.
5.
In contrast to schooling behavior in fish, which is well documented, the schooling behavior of an evolutionary counterpart,
squid, has not been adequately described in the literature. In the current study, we investigated the ontogeny of schooling
behavior in the oval squid Sepioteuthis lessoniana reared from hatching to about two months of age. During the two months of development, the distance and angle between nearest-neighbor
individuals decreased from 5.3 mantle lengths (ML) to 1.8 ML and from 42.7° to 24.2°, respectively. In addition, the swimming
distance of individuals in experimental duration decreased from 530.4 to 79.9 ML, and the relative swimming speed also decreased
from 17.1 to 4.6 ML/s during the same period, with increasing synchronized hovering of individuals. These observations clearly
suggest that oval squid swim randomly until 20 days after hatching, then form a school 30–60 days after hatching with an inter-individual
distance of 2.0 ML. At two months after hatching, oval squid individuals swam in a parallel orientation and formed a belt-shaped
arrangement, similar to the adult schooling behavior observed in natural populations. 相似文献
6.
Chemoattraction and feeding stimulation in crustaceans 总被引：1，自引：0，他引：1
7.
Predator‐prey interactions can be influenced by the behaviour of individual species as well as environmental factors. We conducted laboratory experiments to test for the influences of two abiotic factors (light intensity and habitat complexity) on predator–prey interactions between walleye Sander vitreus and two prey species, bluegill Lepomis macrochirus and golden shiner Notemigonus crysoleucas. Three light intensities were simulated (day, twilight and night) in the presence or absence of simulated vegetation. Observations of predator behaviour indicated that walleye increased activity and foraging success with decreasing light levels and had most success capturing dispersed, closer prey. While schooling could not be maintained as light levels diminished, prey decreased predation vulnerability by moving into vegetation or higher in the water column. Throughout all treatments, bluegill were more evasive to capture as the number of strikes was similar on both prey but capture rates were higher for golden shiner. Although light intensity and simulated habitat complexity affected predator and prey behaviour, these factors did not interact to influence foraging success of walleye. To fully understand predator and prey behaviours in fishes, an understanding of species‐specific responses to abiotic and biotic factors is necessary. 相似文献
8.
Helder Mateus Viana Espírito‐Santo Jefferson Gomes Sodr Jansen Zuanon 《Ecology of Freshwater Fish》2019,28(3):356-364
Amphibious habits are present in a variety of fish and are allowed by a set of physiological, morphological and behavioural adaptations. The most intriguing question, however, is what motivates an aquatic organism to venture into the land? Unfavourable abiotic and biotic conditions in the aquatic environment have been reported as main stimuli for fish to emerge from water. However, few attempts have been made to disentangle the effects of different social contexts on the propensity of amphibious fishes to leave the water. Trying to separate the effects of predator threat, intraspecific competition and mate searching on overland movement of amphibious fish, we ran a mesocosm experiment with the Amazonian killifish Anablepsoides micropus. Overland movement was quantified based on fish leaps between artificial pools set in enclosures in a primary forest area. Males moved overland more frequently than females and their movement depended on the social context, being higher in the presence of predators and lower in the presence of females. Females, instead, showed context‐independent movement rates. This suggests that males move between pools searching for mates, stopping when successful in this search. On the other hand, occasional encounters with predators may force males to abandon the pool as a defence mechanism. Female aggressiveness towards the predator may influence its low movement in the presence of the predator. Such differential responses may play important ecological and evolutionary roles, allowing A. micropus to occupy a wide range of environmental conditions under varied ecological and social contexts. 相似文献
9.
Collin D. Smith John M. Plumb Noah S. Adams Garth J. Wyatt 《Fisheries Management and Ecology》2021,28(2):172-182
Quantifiable estimates of predator–prey interactions and relationships in aquatic habitats are difficult to obtain and rare, especially when individuals cannot be readily observed. To overcome this observational impediment, imaging sonar was used to assess the cooccurrence of predator-size fish and juvenile salmonids, Oncorhynchus spp., at the entrance to a floating surface collector (FSC) in the forebay of North Fork Dam on the Clackamas River, Oregon (USA). Imaging sonar can be used to transform active sound waves into visual data, making it possible to obtain continuous underwater observations on the presence and interspecific interactions between predator-size fish and prey (juvenile salmonids). Hourly counts of smolt-size fish tracks, diel phase, water clarity and river discharge were used as covariates within a zero-inflated Poisson model to determine how these factors may influence the number of predators in front of the FSC. Both the number of smolt-size fish tracks and diel phase had the strongest effects on the number of predator-size fish tracks, with more predator-size fish tracks observed during the daytime, and as the number of smolt-size fish tracks increased. Additionally, the presence of predator-size fish may affect the abundance and direction of travel of juvenile salmonids, as fewer smolt-size fish were observed when predators were present, and a greater proportion of smolt-size fish were observed travelling away from the FSC when predator-size fish were present. This study provides estimates of predator and prey fish abundance in the vicinity of surface collection systems at moderate-sized hydropower projects and could help resource managers better understand mechanisms that can influence the survival and passage behaviour of juvenile salmonids using surface collection structures at dams. 相似文献
10.
Dynamics of intracohort cannibalism in cultured fish 总被引：1，自引：1，他引：1
Abstract Cannibalism is a frequent phenomenon in fish, especially in culture environments where fish are unable to escape predation via habitat segregation or migration. Not all cultured fish species start to exhibit cannibalism at the same age or size, nor is cannibalism equally intense in different species or life stages. Predator to prey size ratios vary substantially between species and life stages, chiefly because cannibalism is governed by gape size limitations and allometric growth of mouthparts. The development of sense organs, hard body parts, swimming and escape capacities in both the predator and the prey also influence prey size selectivity. The dynamics of cannibalism are influenced by these, as well as by environmental, factors that have effects on feed intake, growth depensation and facilitate or complicate the displaying of cannibalistic behaviour. Knowledge about cannibalistic behaviour and the logistics of cannibalism along with environmental enhancement are prerequisites for the mitigation of cannibalism in aquaculture. Also, within the context of strain selection, it is of importance to determine whether cannibals are natural‐born killers or just lottery winners. These factors are discussed, chiefly as they apply to intracohort cannibalism. In addition, guidelines are suggested for cannibalistic risk assessment, and methods for mitigation of cannibalism are discussed. 相似文献
11.
Luciana L. Santos Naraiana L. Benone Bruno E. Soares Ronaldo B. Barthem Luciano F. A. Montag 《Ecology of Freshwater Fish》2019,28(3):424-433
Studies of trait–environment relationships provide important tools for the prediction of the response of biological communities to environmental alterations. The Amazon basin presents enormous potential for the development of research on this type of relationship, given the diversity of both its fish fauna and the aquatic ecosystems this fauna inhabits. The present study investigated the association between local environmental variables and the functional traits of fish in 54 streams of six major Amazonian basins. We identified the relationship between the characteristics of the streams (channel morphology, channel habitat units, riparian vegetation cover, large woody fragments and instream cover for aquatic organisms) and fish traits related to locomotion, habitat use and feeding behaviour. The fish fauna of the broader, deeper and more slowly flowing streams was dominated by nektobenthic species that exploit autochthonous resources such as fish and invertebrates. In narrow, fast‐flowing streams, by contrast, there was a predominance of benthic fishes with varying feeding habits, including periphytivorous and invertivorous species. Narrow, shady streams were inhabited by nektonic species adapted for the exploitation of resources from the marginal vegetation. The results of this study contribute to the understanding of the association between the functional structure of fish assemblages and local environmental variables in Amazonian streams. We hope that these findings will stimulate further research into the natural variation in stream fish assemblages that will ensure the development of more effective management strategies that better protect these important aquatic ecosystems. 相似文献
12.
The effects of food competition and relative size of group members on growth of sea bream, Sparus aurata were tested in groups composed of four fish. Each group consisted of a medium sized test fish (approximately 250 mg) and three fish larger or smaller than the test fish. In the first experiment food competition was addressed directly by contrasting its presence with its absence. Neither food competition nor relative size of school members had a significant effect on growth. However, there was a highly significant interaction between these two main effects. Under conditions of food competition the medium sized test fish had a three times higher specific growth rate when surrounded by small vs large fish. Under conditions of no food competition when the test fish were separated during feeding a similar but reverse pattern occurred due to differences in food conversion efficiency. In the second experiment, the effects of food quantity and relative size of group members were tested. Both main effects and their interaction were highly significant. Under conditions of low food competition (i.e., surplus food supply) fish grew again better when surrounded by larger fish as compared to their growth rate when surrounded by smaller ones. Size matching via a differential growth rate in a schooling species such as sea bream was suggested to increase the confusion effect by reducing the ability of a predator to focus on an odd sized fish. The implications of direct competition for food for the efficient culture of this species are discussed. 相似文献
13.
Kei’ichiro Iguchi 《Ecology of Freshwater Fish》2012,21(1):1-11
Abstract – Social and foraging modes in fish often vary between individuals with different body sizes and between populations under different ecological conditions. We studied social and foraging behaviour of algae‐grazing fish Plecoglossus altivelis ryukyuensis (Ryukyu‐ayu) inhabiting Japanese subtropical island streams. Ryukyu‐ayu exhibited four behavioural modes: territorial, schooling, solitary and floating. Their body sizes differed among these modes. Territorial fish predominantly foraged on benthic algae, whereas schooling and solitary individuals frequently consumed drifting materials as well. Schooling fish were smaller than territorial fish, but, unlike some other algae‐grazing fish species, did not use schooling to gain access to food within territories. Territorial fish attacked smaller conspecifics but exhibited lateral display towards larger fish and schooling fish while occasionally attacking grazing gobies. Larger fish maintained larger feeding territories and occupied territories for longer periods than smaller fish did. This suggests that, in Ryukyu‐ayu, intra‐ and interspecific food competitions and relative body size can influence diverse behavioural modes and duration of territory occupation. We also found that Ryukyu‐ayu foraged more often and had larger feeding territories than ayu P. a. altivelis inhabiting temperate streams. We conclude that foraging strategies of Ryukyu‐ayu may have adapted to subtropical island streams, where algal productivity is much lower than that in temperate regions. 相似文献
14.
Abstract – The efficiency of a Passive Integrated Transponder (PIT)-tag detection system was tested during a 23-day experiment using a permanent digital video to record the passage of fish through multiplexed antennas. Coupling video to the PIT system allowed the detection of error sources and the correction of erroneous data. The efficiency of the detection system and its variation were investigated according to fish swimming speed, direction of movement and individual fish behaviour. Influence of time and environmental conditions on detection results were also checked. The PIT tag system was 96.7% efficient in detecting fish. Upstream movements were better detected (99.8%) than downstream movements (93.7%). Moreover, results showed that efficiency rate was not stable over the experiment; it was reduced on stormy days. Several sources of errors were identified such as sub-optimal orientation of the PIT tag relative to the antenna plane, the influence of fish swimming speed, individual fish behaviour and influence of environmental conditions. 相似文献
15.
BORI L. OLLA MICHAEL W. DAVIS CLIFFORD H. RYER SUSAN M. SOGARD 《Fisheries Oceanography》1996,5(S1):167-178
This review summarizes results of an extensive series of laboratory studies on the behavioural responses of early life stages of walleye pollock, Theragra chakogramma to key environmental factors including light, temperature, gravity, turbulence, food availability and predator presence. Experiments focused on vertical distribution of egg through 0-age stages, and social interactions of age-0 juveniles. Key factors were modified either singly or in concert to determine their direct and indirect influence on fish behaviour. The observed results suggest that the behaviour of individual fish depends on the integration of a continually changing hierarchy of both intrinsic and extrinsic factors, with the relative importance of a specific factor varying with ontogeny and over time and space. The broad range of responses displayed by early life stages suggests that behaviour plays an important role in determining the consequences of environmental variability on walleye pollock populations. In general, results from our laboratory experiments are consistent with patterns observed in field studies, supporting the efficacy of using experimental behavioural research to define some of the underlying mechanisms controlling distribution and survival in the field, and eventual recruitment to adult populations. 相似文献
16.
Fish telemetry in aquaculture: review and perspectives 总被引：4，自引：0，他引：4
The assessment of the behaviour or physiology of cultured fish has always been difficult due to the timing of sampling, differences between experimental and aquaculture conditions and to methodological bias arising from repeated fish handling. The development of biotelemetry techniques offers a wide range of possibilities to improve both production and management in aquaculture through monitoring of behaviour or physiology of free-swimming fish inside their culture environment. Thus knowing how key parameters are changing can allow faster adjustment of feeding times to activity rhythms, more objective identification of the preference/tolerance margins towards environmental variables and precise assessment (from the fish's point of view) of the impact of environmental or operational stressors on fish. This paper briefly reviews the techniques that might be applied in aquaculture and focuses on relevant systems and estimators of fish activity: movements, vertical distribution, use of demand-feeders, muscular activity and heart rate. Species or size-related limitations and use of automatic monitoring stations are reviewed and evaluated. Perspectives of integrated biomonitoring in aquaculture are discussed, using telemetered fish as reliable probes in the detection of abnormal situations such as changes of water quality or altered environments. 相似文献
17.
Leadership is not an inherent quality of animal groups that show directional locomotion. However, there are other factors that may be responsible for the occurrence of leadership in fish shoals, such as individual differences in nutritional state between group members. It appears that front fish have a strong influence on directional shoal movements and that individuals that occupy such positions are often characterised by larger body lengths and lower nutritional state. Potential interactions between the two factors and their importance for positioning within shoals need further attention. Initiation of directional movement in stationary shoals and position preferences in mobile shoals need to be addressed separately because they are potentially subject to different constraints. Individuals that initiate a swimming direction may not necessarily be capable of the sustained high swimming performance required to keep the front position or have the motivation to do so, for that matter. More empirical and theoretical work is necessary to look at the factors controlling positioning behaviour within shoals, as well as overall shoal shape and structure. Tracking of marked individuals whose positioning behaviour is monitored over extended time periods of hours or days would be useful. There is an indication that shoal positions are rotated by individuals according to their nutritional needs, with hungry fish occupying front positions only for as long as necessary to regain their nutritional balance. This suggests that shoal members effectively take turns at being leaders. There is a need for three‐dimensional recordings of shoaling behaviour using high‐speed video systems that allow a detailed analysis of information transfer in shoals of different size. The relationship between leadership and shoal size might provide an interesting field for future research. Most studies to date have been restricted to shoals of small and medium size and more information on larger shoals would be useful. 相似文献
18.
Martins CI Galhardo L Noble C Damsgård B Spedicato MT Zupa W Beauchaud M Kulczykowska E Massabuau JC Carter T Planellas SR Kristiansen T 《Fish physiology and biochemistry》2012,38(1):17-41
Behaviour represents a reaction to the environment as fish perceive it and is therefore a key element of fish welfare. This review summarises the main findings on how behavioural changes have been used to assess welfare in farmed fish, using both functional and feeling-based approaches. Changes in foraging behaviour, ventilatory activity, aggression, individual and group swimming behaviour, stereotypic and abnormal behaviour have been linked with acute and chronic stressors in aquaculture and can therefore be regarded as likely indicators of poor welfare. On the contrary, measurements of exploratory behaviour, feed anticipatory activity and reward-related operant behaviour are beginning to be considered as indicators of positive emotions and welfare in fish. Despite the lack of scientific agreement about the existence of sentience in fish, the possibility that they are capable of both positive and negative emotions may contribute to the development of new strategies (e.g. environmental enrichment) to promote good welfare. Numerous studies that use behavioural indicators of welfare show that behavioural changes can be interpreted as either good or poor welfare depending on the fish species. It is therefore essential to understand the species-specific biology before drawing any conclusions in relation to welfare. In addition, different individuals within the same species may exhibit divergent coping strategies towards stressors, and what is tolerated by some individuals may be detrimental to others. Therefore, the assessment of welfare in a few individuals may not represent the average welfare of a group and vice versa. This underlines the need to develop on-farm, operational behavioural welfare indicators that can be easily used to assess not only the individual welfare but also the welfare of the whole group (e.g. spatial distribution). With the ongoing development of video technology and image processing, the on-farm surveillance of behaviour may in the near future represent a low-cost, noninvasive tool to assess the welfare of farmed fish. 相似文献
19.
Early research into the causes of geographical variation in antipredator behaviour in fishes revealed that population differences have an underlying genetic basis. However, evidence from a variety of fish species suggests that learning plays an important role in the development of antipredator responses. Here, we consider the opportunities for learning during the three main stages of a predator–prey interaction: detection, recognition and assessment, and attack avoidance. Much of the evidence for learning is based on the recognition and assessment stage of the predator–prey interaction, but this may reflect methodological biases. We also examine the relative roles of different sensory cues, in particular, vision and olfaction, and the importance of individual vs. social learning. We provide evidence that visual predator recognition skills are largely built on unlearned predispositions, whereas olfactory recognition typically involves experience with conspecific alarm cues. Populations display variation in their propensity to learn, and we predict that ecological factors are likely to mediate the balance between individual and social learning. 相似文献
20.
《水生生物资源》2000,13(4):193-202
This article describes tracking experiments conducted on eleven yellowfin tuna using ultrasonic transmitters in French Polynesia between 1985 and 1997. Nine fish were caught near Fish Aggregating Devices (FADs) while the other two were tracked in coastal areas without FADs. The fish showed different patterns of horizontal movements: tight associations with FADs lasting several days, foraging movements confirmed by simultaneous acoustic observations of prey-sized fauna, movements parallel to the shore, and traveling between FADs. This intra- and inter-individual variety of behaviour might depend on the local environment (prey), and on individual biological differences. The influence of FADs, coastlines, and prey on tuna movements is discussed. The lack of information about the surrounding environment, the internal state of the fish and the recent history of the fish usually prevent scientists from adequately interpreting the observed movements. Ideas for future research to studying tuna behaviour near FADs are discussed. 相似文献